In the field of printing, the most common type printer has been the printer which impacts against record media that is caused to be moved past a printing line or line of printing. As is well-known the impact printing operation depends upon the movement of impact members, such as print hammers or wires or the like, which are typically moved by means of an electromechanical drive system and which system enables precise control of the impact members.
In the field of dot matrix printers, it has been quite common to provide a print head which has included therein a plurality of print wire actuators or solenoids arranged or grouped in a manner to drive the respective print wires a very short, precise distance from a rest or non-printing position to an impact or printing position. The print wires are generally either secured to or engaged by the solenoid plunger or armature which is caused to be moved such precise distance when the solenoid coil is energized and wherein the plunger or armature normally operates against the action of a return spring.
It has also been quite common to provide an arrangement or grouping of such solenoids in a circular configuration to take advantage of reduced space available in the manner of locating the print wires in that specific area between the solenoids and the front tip of the print head adjacent the record media. In this respect, the actuating ends of the print wires are positioned in accordance with the circular arrangement and the operating or working ends of the print wires are closely spaced in vertically-aligned manner adjacent the record media. The availability of narrow or compact actuators permits a narrower or smaller print head to be used and thereby reduces the width of the printer because of the reduced clearance at the ends of the print line. The print head can also be made shorter because the narrow actuators can be placed in side-by-side manner closer to the record media for a given amount of wire curvature.
In the wire matrix printer which is utilized for receipt and for journal printing operations, the print head structure may be a multiple element type and may be horizontally disposed with the wire elements aligned in a vertical line and supported on a print head carriage which is caused to be moved or driven in a horizontal direction for printing in line manner across the receipt or journal paper and wherein the drive elements or transducers may be positioned in a circular configuration with the respective wires leading to the front tip of the print head. In the wire matrix printer which is utilized for business forms or like record media printing operation, the print head may be oriented in a manner wherein the nose is pointed downward for printing on the form, slip or like record media while the carriage and print head are moved above and across the form or like record media in the horizontal direction.
Further, in the wire matrix printer which is utilized for receipt, slip and journal printing operations, the individual print heads may be vertically oriented and printing performed by means of the print wires moving downwardly to impact on the record media. Alternatively, the individual print heads may be horizontally oriented and printing performed by means of the print wires moving horizontally to impact on the record media. A preferred number of four of such individual print heads is common in known arrangements.
The dot matrix printer is commonly used in an electronic cash register (ECR) or in a point of sale (POS) terminal. The register or the terminal includes means for guiding the receipt and means for guiding the slip past the printing station and the guiding means is selected in a manner dependent upon the printing operation.
The printer in an ECR or a POS terminal has the function of printing a receipt which is handed to the customer and also has the function of printing a journal which is retained as a record of the transaction. Additionally, the printer may have the function of printing on a slip or like form which is used in certain retail operations. Separate printers have been used for printing the receipt, the journal and the slip. Other arrangements have used one or two printers respectively having two or three printing functions and commonly referred to as multifunction printers. A roll of paper is used for the receipt printing and a roll of paper is used for the journal printing, whereas a slip may consist of a single sheet or a form may consist of a set of sheets.
In apparatus of the type wherein printing on receipts, journals and slips is performed by one printer, there is provided a dual printing mechanism. Printing on the journal paper is performed by one printing mechanism and printing on the receipt and/or slip is performed by the other printing mechanism of the printer. In some cases, printing on the receipt and on the slip is performed by one printer and printing on the journal is performed by another printer.
In the printer mentioned above wherein printing is performed on the receipt and/or slip by the other printing mechanism, a special device is required for switching the printing function from receipt printing to slip printing or from slip printing to receipt printing. Additionally, means is required for controlling the operation of the special device.
Representative documentation in the field of guide mechanisms includes U.S. Pat. No. 4,197,023, issued to J. L. DeBoo et al. on Apr. 8, 1980, which discloses a rigid paper guide chute having a flexible member secured thereto and extending around a platen a sufficient distance to assure that the paper is directed past the print mechanism and through an exit.
U.S. Pat. No. 4,234,261, issued to W. Hendrischk et al. on Nov. 18, 1980, discloses drives and paths for paper web or for individual forms. Switches are provided along the paths for controlling the flow of the web or form.
U.S. Pat. No. 4,586,839, issued to F. Iwagami on May 6, 1986, discloses an upper paper guide and a lower paper guide integrated as one device and rotatably supported to provide a path for the paper and to permit removal of the platen.